Chair height control

ABSTRACT

A chair height control having an outer non-rotatable tube fixed to the chair base or legs, an innermost longitudinally telescoping tube supporting the chair seat, and an intermediate locking tube rotatable with respect to the fixed tube, by suitable bearing means incorporated within the fixed tube, and a releasable catch means is provided within the innermost longitudinally extendible tube, which is releasably operable from immediately beneath the seat, and provided for interlocking engagement with a series of recesses in the intermediate tube, whereby the innermost tube can be extended or retracted with respect to the intermediate tube, and fastened in any desired height, and, when fastened in position, both the inner tube and the intermediate tube rotate together in unison with relation to the outer fixed tube.

O nlted States Patent 11 1 1111 3,712,574

Rothermel 1 1 Jan. 23, 1973 CHAIR HEIGHT CONTROL Primary Examiner-William H. Schultz Atlorney-George A. Rolston [76] Inventor: Heinz Rothermel, 604 W. Bloor Street, Apt. 13, Toronto, Ontario, [57] ABSTRACT Canada I A chair height control having an outer non-rotatable [22] Filed: Dec. 1, 1970 tube fixed to the chair base or legs, an innermost longitudinally telescoping tube supporting the chair seat, [21] Appl. No.: 94,105 and an intermediate locking tube rotatable with respect to the fixed tube, by suitable bearing means in- [52 U.S. c1. ..24s/409 commated within the fixed and a releasable 51 Int. Cl ....Fl6m 11/04 catch means is pmvided within F i'memwst [58] Field Search "248N882, 188] 407, 408, dinally extendible tube, which is releasably operable 248/409 from immediately beneath the seat, and provided for interlocking engagement with a series of recesses in [56] Refe'rences Cited the intermediate tube, whereby the innermost tube f can be extended or retracted with respect-to the inter- ,UNITEDSTATES PATENTS mediate tube, and fastened in any desired height, and, 354,469 12/1886 Gould ..24s/295 when fastened positim" the inner tube and the 320.437 6/1885 Matthieu intermediate tube rotate together in unison with rela- '493 1 1 tion to the outer fixed tube.

SH 893 Parsons ..248/409 6 Claims, 4 Drawing Figures PATENTED JAN 2 3 I975 SHEET 1 [IF 2 Inventor HEIINZ ROTHERMEL PATENTED JAN 23 I975 SHEET 2 OF 2 Inventor HEINZ ROTHERMEL by: m

CHAIR HEIGHT CONTROL The present invention relates to a chair height or seat support column such as is used on steno chairs and the like in which the support column is of an adjustable height, and preferably although not exclusively to chairs of this type in which the seat is provided with a certain limited upward and downward spring action to provide a degree of resiliency for the occupier.

BACKGROUND OF THE INVENTION Adjustable chairs such as steno chairs which are currently on the market, normally employ a simple form of telescoping column device, one of the columns being threaded and provided with a rotatable threaded collar, by means of which the inner column may be extended with relation to the outer column. The threaded devices are incorporated with a rotatable bearing so that the chair may be swivelled around in use. Such relatively simple forms of adjustable height chair incorporate various disadvantages. in order to adjust the height of the chair the occupier must get off it, kneel down beside it and rotate the rotatable threaded device by hand for a few turns and then sit on the chair once more to determine if the height is more or less right. This relatively clumsy inconvenient procedure must be repeated each time a new occupier takes over the chair. Normally, the rotatable bearing, which permits the chair to swivel around must be oiled from time to time and it is common for the oil to weep out and run down the sides of the column. As a result, every time the height of the chair is adjusted the occupier dirties his or her hands, and a further delay is involved while the hands are cleaned. Clearly, although such devices are relatively speaking economical to make, in that they involve a small number of moving parts, the function leaves much to be desired. However, in recent years, the production of the threaded inner column of this type of device has become increasingly expensive due to increases in wages and the like, and it has become desirable to find some other form of height adjustment which does not require the threading of a relatively lengthy tube.

Other forms of more complex adjustable height chairs have been available and have been proposed in earlier patents, incorporating alternative means of height adjustment for example, by a spring loaded button device seating in a series of recesses, in one case, and in another case, incorporating an adjustable spring supporting the upper portion of the telescoping column, providing the occupier of the seat with a certain resiliency or cushioning effect. Although such earlier devices avoided some of the short comings of the relatively crude threaded extension device, they were much more expensive, and in addition did not always provide the desired combination of functions. Thus in some cases, although the threaded extension device was replaced by a spring loaded plunger, it was necessary to get off the chair to release the plunger to enable the chair to be raised 'or lowered, since the plunger formed part of the lower column which remains stationary, while the seat portion of the chair moved upwardly and downwardly. An example of this type of chair is shown in U.S. Letters Patent 2,659,413.

In another form of chair the plunger or catch release means was incorporated in the upper column, and

located immediately beneath the seat so that it could in fact be operated by the occupier of the seat without moving from the seat itself, simply by reaching underneath the seat and operating the catch. An example of such a device is shown in U.S. Letters Patent 2,016,132. However, in such earlier devices of this type, the rotatable bearing means permitting the seat to be swung around were totally insufficient for any extended use, and would require repeated oiling to function satisfactorily and in any event did not incorporate any resilient means in the supporting column to cushion the seat. In addition, since it was necessary to provide a certain degree of clearance between the rotatable tube and the non-rotatable tube, as the rotatable tube became fully extended with relation to the non-rotatable tube the seat tended to wabble and become unstable.

BRIEF SUMMARY OF THE INVENTION With a view to overcoming these various disadvantages, the invention generally resides in the provision of an outer non-rotatable tube fixed to the chair base or legs, an innermost longitudinally telescoping tube supporting the chair seat, and an intermediate locking tube rotatable with respect to the fixed tube, by suitable'bearing means incorporated within the fixed tube, and a releasable catch means provided within the innermost longitudinally extendible tube, which is releasably operable from immediately beneath the seat, and provides for interlocking engagement with a series of recesses in the intermediate tube, whereby the innermost tube can be extended or retracted with respect to the intermediate tube, and fastened in any desired height, and, when fastened in position, both the inner tube and the intermediate tube rotate together in unison with relation to the outer fixed tube. Preferably according to the invention, the intermediate tube is spring loaded within the outer fixed tube, so as to provide a certain limited springing or cushioning action for the occupier.

Further and other objectives and advantages will become apparent from the following description of a preferred embodiment which is given here by way of example only and with reference to the following drawings in which like reference devices refer to like parts thereof throughout the various views and diagrams.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view, partially in section, of the adjustable chair base according to the invention, with part thereof shown in phantom;

FIG. 2 is a perspective illustration, partially cut away of a portion of the mechanism as shown in FIG. 1;

FIG. 3 is a section along the line 3-3 of FIG. 1, and,

FIG. 4 is a section along the line 4-4 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The chair elevation system as now described is believed to be particularly suitable for use in association with a chair such as a steno chair, the basic features of which are very well known in the art and do not require illustration or description. Thus such a chair will incorporate in the normal way a seat cushion, a back support cushion supported at an elevation above the seat cushion, and frequently be provided with upward and downward adjustment to suit the occupier of the chair, and sometimes be spring loaded to permit the same to swing forward and rearwardly. Usually, such a chair is provided with a central support column or chair base extending downwardly more or less from the seat squab, and provided at its lower end with four chair legs extending outwardly in a more or less radial manner, and being provided at their free ends with casters so that the chair is free to move about. Obviously, the invention is not restricted solely to use on a steno chair but will find application in any circumstances where it is desired to provide a chair or seat with an elevation control.

Referring now to the drawings, it will be seen that the adjustable chair base according to the invention comprises a central column referenced as 10, provided at its lower end with legs 11, only portions of which are shown, the remainder being omitted for the sake of clarity, and which are provided at their'ends with any suitable casters or other means suitable for the particular purpose for which the chair is designed-At the upper end of the column there is provided a generally dish shaped sheet metal seat bearing member 12, contoured and shaped around its peripheral flange 13 to engage the underside of a seat cushion (not shown) of a typical chair. V

The support column 10 will be seen to comprise the fixed outer tubular column member 14, the lower end of which is attached. to the legs 11 by welding or any other suitable means, and which is provided in the lower portion thereof with a thickened wall section defining an inwardly directed ledge means 15 extending around the interior thereof for the purposes to be described. Attached to the seat support member '12, there is the interior seat support tube 16, extending through an opening in the center of the seat support member 12, and fastened therein by means of upper and lower flanged collars 17 and 18 welded in position to the seat support member 12, and to tube 16 to ensure rigid attachment therebetween. It will be noted that the interior of the tube 16 is open to the interior of the seat support member 12, and that it terminates short of the level of the flange 13 for purposesto be described.

Around the tube 16, and within the column 14 there is provided the intermediate locating sleeve 19, having an interior diameter adapted to make a snug sliding fit with the tube 16, whereby tube 16 may be telescoped inwardly and outwardly relative thereto, while being supported by such sleeve 19 against tilting movement from side to side at substantially all elevations. The sleeve 19 is located and supported rotatably relative to the column 14, by means of the upper locating ring 20, press fitted into the upper open end of the column 14, and rotatably receiving the sleeve 19 therethrough. It will be noted that the sleeve 19 extends upwardly through the ring 20, a predetermined distance for reasons to be described below. The sleeve 19 is further supported by means of the upper fixed collar 21 welded or press fitted to the exterior of the sleeve 19, and provided with an upper flange 22 thereon. Support spring 23 engages the underside of the flange 22 of the collar 21 as shown, and at its lower end is received on the annular washer member 24. The annular washer member 24 constitutes the uppermost portion of a freely rotatable bearing system, the remainder of the system comprising the roller bearing race 25, having a plurality of bearing rollers 26 located therearound, and running on the lower annular washer 27. Washer 27, and the bearing race 25 are supported on the fixed annular plug member 28 provided with a shoulder 29 adapted to rest on the ledge 15 within the outer column 14. The lower end of the intermediate sleeve 19 is closed off by means of the end closure cap 30 pressed fitted over the end of the sleeve 19.

In this way, the intermediate sleeve 19 will be seen to be supported by the spring 23 the bearing 25 and the plug member 28 within the outer column 14, and to be resiliently movable downwardly against the pressure of the spring 23. At the same time, it is also freely rotatable within the column 14, the roller bearing race 25 being of such a nature that it will require no lubrication throughout the use of the chair, and being so located and concealed that it will not become rendered useless by dust or other foreign matter.

In order to lock the innermost tube 16 at any desired extension with relation to the intermediate sleeve 19, the sleeve 19 is provided with a plurality of locking holes or notches 31, arranged longitudinally up one side of the sleeve 19 in line with one another, and at the lower end of the innermost tube 16, a registering opening 32 is provided adapted to register with any one of the notches 31.

. Within the tube 16, there is provided the locking support bar 33 pivotally mounted within the sleeve 16 on the pivot bar 34, and provided at its lower end with a locking member or tooth 35 which is shaped and adapted to pass through the opening 32 and into the notches 31. The locking bar 33 is operated by means of the control rod 36 extending upwardly within the tube 16, and the upper end of which extends outwardly from the upper end of tube 16 within the dish shaped member 12. At this point, it is bent over an angle a little more than and this bent portion extends outwardly from the dish shaped member 12 as the operating arm 37, a slot 38 being provided in the side of the dish shaped member 12 to permit movement of the operating arm 37 upwardly and downwardly. Spring 39 is connected between the shaped member 12 andthe control rod 36 so as to draw the same to one side of the tube 16.

In order to limit the outward swinging movement of the lower end of the support bar 33, a control pin 40 extends from side to side of the tube 16, passing through an oversize hole 41 formed in the lower end of the support bar 33, which is dimensioned to provide sufficient freedom of movement to permit the dog 35 to enter the notches 31 in the sleeve 19, but restraining the same from passing completely therethrough.

In order to maintain the tube 16, and its opening 32, in predetermined registration with the sleeve 19 and its notches 31, a guide slot 42 is formed down one side of the sleeve 19, preferably offset approximately 90 therearound with regard to the line of notches 31. The control pin 40 is provided with an endwise extension or tongue member 43 shaped and adapted to extend outwardly from the side wall of the tube 16, and ride in the slot 42, thereby preventing rotation of the tube 16 relative to the sleeve 19.

in operation, when a person sits on the chair, his weight will be transmitted through the tube 16, and the supporting bar 33, and the dog 35 to the sleeve 19. The sleeve 19 will thereupon move downwardly compressing the spring 23, between the upper fixed collar 22, and the annular bearing washer 24. When the person wishes to swing the seat around, such rotational movement will be transmitted in the same way, that is to say, via the tube 16 to the sleeve 19, and the sleeve 19 will rotate freely around, with the roller bearing race 25 moving sufficient to permit such movement, and the upper end of the sleeve 19 riding in the upper locating ring 20.

When the occupier wishes to move the chair to a different height, all that is necessary is to momentarily rise upwardly off the seat, and then simply take hold of the handle 37 and lift it upwardly against the underside of the seat. Upward movement of the handle 37 wild swing the control rod 36 across the interior of the tube 16, causing the support bar 33 to swing in the opposite direction about the pivot bar 34, and thereby withdrawing the dog 35 from the notch 31 in the sleeve 19. The

seat is then free to be raised upwardly or pushed downwardly, and when the desired height is reached the handle 37 is simply released, and a small adjusting movement of the seat either upwardly or downwardly will then permit the spring 39 to operate the control rod 36 in the reverse direction and cause the dog 35 to lodge in the nearest notch 31.

The foregoing is a description of a preferred embodiment which is given here by way of example only.

The invention is not to be taken as limited to any of the specific features as described but comprehends all such variations thereof as come within the scope of the appended claims.

What I claim is:

l. A chair height control apparatus adapted for use in association with posture-type chairs, seats, and the like such as office chairs, supported on a base or legs and comprising;

outer fixed column means adapted to be attached to any suitable base means and defining a hollow interior;

inner movable tube means slidable within said column means, and extendable therefrom;

chair seat support means mounted on the upper end of said tube means and adapted d to be attached to a chair seat;

intermediate rotatable sleeve means located at least partially within said column means and slidably receiving said tube means therein;

bearing means rotatably supporting said sleeve means within said column means;

adjustable fastening means adapted to releasably lock said inner movable tube means within said intermediate rotatable sleeve means at differing heights, and, spring means fastened by one end around the exterior of said intermediate rotatable sleeve means, and at its other end, being rotatably supported on said bearing means within said column means whereby said sleeve means is rotatably supported through said spring means, on

said bearin means as aforesaid, permitting the same to be s 1d downwardly against he pressure of said spring, and rotated relative to said outer fixed column means.

2. Apparatus as claimed in claim 1 including support means within said outer fixed column means locating and supporting said bearing means therein.

3. Apparatus as claimed in claim 1 wherein said inner movable tube means is open at its upper end at least, and providing access to the interior thereof from within said chair seat support means.

4. Apparatus as claimed in claim 1 wherein said sleeve means extends into said column means a substantial distance, and including a plurality of locking openings formed therein in substantially vertical alignment with one another, and including releasable locking means mounted within said tube means, and extensible therefrom into engagement with a selected one of said openings, to secure said tube relative to said sleeve means.

5. Apparatus as claimed in claim 1 including operating arm means extending outwardly from said chair seat support means, and operable from immediately beneath the chair seat attached thereto, and means interconnecting said operating arm means with said adjustable fastening means, whereby said adjustable fastening means can be released by operation of said operating arm means. i

6. Apparatus as claimed in claim 1 including guide means connecting between said inner tubular member and said sleeve means maintaining same in predetermined alignment with one another. 

1. A chair height control apparatus adapted for use in association with posture-type chairs, seats, and the like such as office chairs, supported on a base or legs and comprising; outer fixed column means adapted to be attached to any suitable base means and defining a hollow interior; inner movable tube means slidable within said column means, and extendable therefrom; chair seat support means mounted on the upper end of said tube means and adapted to be attached to a chair seat; intermediate rotatable sleeve means located at least partially within said column means and slidably receiving said tube means therein; bearing means rotatably supporting said sleeve means within said column means; adjustable fastening means adapted to releasably lock said inner movable tube means within said intermediate rotatable sleeve means at differing heights, and, spring means fastened by one end around the exterior of said intermediate rotatable sleeve means, and at its other end, being rotatably supported on said bearing means within said column means whereby said sleeve means is rotatably supported through said spring means, on said bearing means as aforesaid, permitting the same to be slid downwardly against the pressure of said spring, and rotated relative to said outer fixed column means.
 2. Apparatus as claimed in claim 1 including support means within said outer fixed column means locating and supporting said bearing means therein.
 3. Apparatus as claimed in claim 1 wherein said inner movable tube means is open at its upper end at least, and providing access to the interior thereof from within said chair seat support means.
 4. Apparatus as claimed in claim 1 wherein said sleeve means extends into said column means a substantial distance, and including a plurality of locking openings formed therein in substantially vertical alignment with one another, and including releasable locking means mounted within said tube means, and extensible therefrom into engagement with a selected one of said openings, to secure said tube relative to said sleeve means.
 5. Apparatus as claimed in claim 1 including operating arm means extending outwardly from said chair seat support means, and operable from immediately beneath the chair seat attached thereto, and means interconnecting said operating arm means with said adjustable fastening means, whereby said adjustable fastening means can be released by operation of said operating arm means.
 6. Apparatus as claimed in claim 1 including guide means connecting between said inner tubular member and said sleeve means maintaining same in predetermined alignment with one another. 